scholarly journals Low defect and high electrical conductivity of graphene through plasma graphene healing treatment monitored with in situ optical emission spectroscopy

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mohammad Salehi ◽  
Parnia Bastani ◽  
Loghman Jamilpanah ◽  
Abbas Madani ◽  
Seyed Majid Mohseni ◽  
...  
Keyword(s):  
Plasma Treatment ◽  
Emission Spectroscopy ◽  
Optical Emission Spectroscopy ◽  
Optical Emission ◽  
Post Treatment ◽  
Structural Defects ◽  
Pressure Plasma ◽  
Grown Graphene ◽  
Underlying Mechanisms

AbstractFundamental studies on graphene (Gr) and its real device applications have been affected by unavoidable defects and impurities which are usually present in synthesized Gr. Therefore, post treatment methods on Gr have been an important subject of research followed by the community. Here, we demonstrate a post-treatment of cm-sized CVD-grown graphene in a Radio Frequency-generated low-pressure plasma of methane and hydrogen to remove oxygen functional groups and heal the structural defects. The optimum plasma treatment parameters, such as pressure, plasma power, and the ratio of the gases, are optimized using in-situ optical emission spectroscopy. This way we present an optimal healing condition monitored with in situ OES. A twofold increase in the conductivity of plasma-treated Gr samples was obtained. Plasma treatment conditions give insights into the possible underlying mechanisms, and the method presents an effective way to obtain improved Gr quality.

scholarly journals Machine Learning Prediction of Electron Density and Temperature from Optical Emission Spectroscopy in Nitrogen Plasma

Coatings ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1221
Author(s):  
Jun-Hyoung Park ◽  
Ji-Ho Cho ◽  
Jung-Sik Yoon ◽  
Jung-Ho Song
Keyword(s):  
Machine Learning ◽  
Electron Temperature ◽  
Real Time ◽  
Electron Density ◽  
Emission Spectroscopy ◽  
Optical Emission Spectroscopy ◽  
Optical Emission ◽  
Plasma Parameters ◽  
Plasma Nitridation

We present a non-invasive approach for monitoring plasma parameters such as the electron temperature and density inside a radio-frequency (RF) plasma nitridation device using optical emission spectroscopy (OES) in conjunction with multivariate data analysis. Instead of relying on a theoretical model of the plasma emission to extract plasma parameters from the OES, an empirical correlation was established on the basis of simultaneous OES and other diagnostics. Additionally, we developed a machine learning (ML)-based virtual metrology model for real-time Te and ne monitoring in plasma nitridation processes using an in situ OES sensor. The results showed that the prediction accuracy of electron density was 97% and that of electron temperature was 90%. This method is especially useful in plasma processing because it provides in-situ and real-time analysis without disturbing the plasma or interfering with the process.

scholarly journals Analysis of Optical Emission Spectra during Nitrogen-Plasma Treatment to Control the Wettability of Polystyrene Surface

2021 ◽  
Vol 20 (3) ◽  
Author(s):  
Masruroh ◽  
Dionysius J. D. H. Santjojo ◽  
Ahmad Taufiq
Keyword(s):  
Plasma Treatment ◽  
Emission Spectroscopy ◽  
Optical Emission Spectroscopy ◽  
Optical Emission ◽  
Nitrogen Plasma ◽  
Chamber Pressure ◽  
Treatment Results ◽  
Plasma Species ◽  
Dc Bias ◽  
Nitrogen Treatment

In this work, we apply optical emission spectroscopy to investigate active plasma species to study that plasma nitrogen treatment affects polystyrene surfaces. Data concerning these active plasma species are crucial for exploring the polystyrene layer's functionality deposited on quartz crystal microbalance (QCM) surface. Wettability function in biosensors development is essential aspects for biomolecule immobilization. The surface of the polystyrene layer was modified by plasma nitrogen treatment. The process parameters affecting plasma species and characteristic, and hence the treatment results studied in this work were chamber pressure, flow rate, and DC bias. The plasma analysis was conducted by optical emission spectroscopy. The spectroscopy was utilized to predict the active species of plasma, the electron temperature Te and the electron density Ne. The dominant reactive species was N2+ which go through different plasma interactions and on the polystyrene surface depending on the DC bias voltage, the nitrogen- gas flow rate, and the chamber pressure. The plasma treatment results suggest that the ion bombardment was the dominant mechanism that changes the polystyrene's surface. The plasma behavior and surface interactions were found complex with the variation of the process parameter. Keywords: Electron density, Electron temperature, OES, Nitrogen-plasma treatment, Wettability

Correlation Between In Situ Optical Emission Spectroscopy in a Reactive O2 / AR RF Magnetron Sputtering Discharge and PZT Thin Film Composition

1997 ◽  
Vol 493 ◽  
Author(s):  
F. Ayguavives ◽  
P. Aubert ◽  
B. Ea-Kim ◽  
B. Agius
Keyword(s):  
Thin Film ◽  
Magnetron Sputtering ◽  
Emission Spectroscopy ◽  
Optical Emission Spectroscopy ◽  
Optical Emission ◽  
Rf Magnetron Sputtering ◽  
Nuclear Reaction Analysis ◽  
Nominal Composition ◽  
Film Composition

ABSTRACTLead zirconate titanate (PZT) thin films have been grown by rf magnetron sputtering on Si substrates from a metallic target of nominal composition Pb1.1(Zr0.4 Ti0.6 in a reactive argon / oxygen gas mixture. During plasma deposition, in situ Optical Emission Spectroscopy (OES) measurements show clearly a correlation between the evolution of characteristic atomic emission line intensities (Zr - 386.4 nm, Ti - 399.9 nm, Pb - 405.8 nm and O - 777.2 nm) and the thin-film composition determined by a simultaneous use of Rutherford Backscattering Spectroscopy (RBS) and Nuclear Reaction Analysis (NRA).

scholarly journals Investigation of Biocompatible PEO Coating Growth on cp-Ti with In Situ Spectroscopic Methods

Materials ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 9
Author(s):  
Veta Aubakirova ◽  
Ruzil Farrakhov ◽  
Arseniy Sharipov ◽  
Veronika Polyakova ◽  
Lyudmila Parfenova ◽  
...  
Keyword(s):  
Impedance Spectroscopy ◽  
Spectral Line ◽  
Coating Thickness ◽  
Emission Spectroscopy ◽  
Optical Emission Spectroscopy ◽  
Treatment Time ◽  
Optical Emission ◽  
Functional Materials ◽  
Cp Ti

The problem of the optimization of properties for biocompatible coatings as functional materials requires in-depth understanding of the coating formation processes; this allows for precise manufacturing of new generation implantable devices. Plasma electrolytic oxidation (PEO) opens the possibility for the design of biomimetic surfaces for better biocompatibility of titanium materials. The pulsed bipolar PEO process of cp-Ti under voltage control was investigated using joint analysis of the surface characterization and by in situ methods of impedance spectroscopy and optical emission spectroscopy. Scanning electron microscopy, X-ray diffractometry, coating thickness, and roughness measurements were used to characterize the surface morphology evolution during the treatment for 5 min. In situ impedance spectroscopy facilitated the evaluation of the PEO process frequency response and proposed the underlying equivalent circuit where parameters were correlated with the coating layer properties. In situ optical emission spectroscopy helped to analyze the spectral line evolutions for the substrate material and electrolyte species and to justify a method to estimate the coating thickness via the relation of the spectral line intensities. As a result, the optimal treatment time was established as 2 min; this provides a 9–11 µm thick PEO coating with Ra 1 µm, 3–5% porosity, and containing 75% of anatase. The methods for in-situ spectral diagnostics of the coating thickness and roughness were justified so that the treatment time can be corrected online when the coating achieves the required properties.

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